What's she hiding under there? The Australian supermodel kept covered up in a robe when the cameras were off on the Pirelli short film set

The US-based Australian joked that she might as well make the most of being in the best shape of her life.

'When I’m old I can be like "I used to look like that!" she laughed.

'My granddaughter will be like "Yeah right, granny" but I’ll have the proof!'

Nicole said she doesn't do nude shoots much these days, but she had to make an exception for the tasteful shoot, which is inspired by the erotically-charged style of prolific 1960s photographer Helmut Newton.

'I had the support of my boyfriend (Gary Clark, Jr) and dad, which was nice,' the stunning brunette explained.

Time to tuck away those womanly curves: In the film Nicole makes a transformation from a man to a woman

'It’s a big deal, something I've always wanted to.'

The short film has not yet been released, but Nicole has given fans a sneak peek via her Instagram account.

Meanwhile, she also turned heads this week at the Grand Prix launch in Melbourne, wearing a pair of racy leather knee high boots, which has become her trademark.

She teamed the sizzling footwear with a sheer black dress and kept the bold statement pieces rolling in with a chic black wide-brimmed hat and black beaded handbag.

The supermodel is about to make her big television debut when The Face starts on Fox8 on March 18.

Get your engines running! Nicole wore her trademark over-the-knee boots at the Grand Prix launch in Melbourne this week